Pustules and Vesicles in Infants < 60 days old

Sep 24, 2024

When an infant of <60 days of age presents with skin lesions such as pustules or vesicles and there is a fever, there are algorithms that we can use to predict the chance of a serious bacterial infection (SBI) and to guide management. These include:

Rochester Criteria
Philadelphia Criteria
Boston Criteria
Step-by-Step

When an infant presents with skin lesions but no fever, there is not as much direction available. How should we approach these patients?

In this study (1) we look...

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Rochester Criteria
Philadelphia Criteria
Boston Criteria
Step-by-Step

When an infant presents with skin lesions but no fever, there is not as much direction available. How should we approach these patients?

In this study (1) we look at a potential approach to the afebrile infant (< 60 days old) with pustules and vesicles.

WHAT THEY DID

This was a multicenter, retrospective cohort study, from 6 academic paediatric centres in the US.

Patients had to be 60 days or younger, afebrile and had to be examined by a dermatologist.

Not all patients were ED patients.

70 were in NICU
40 in ED
22 in newborn nursery
51 as inpatients

879 infants < 60 days old were examined by a dermatologist. Of these 183 had skin lesions that were pustules, vesicles and/or bullae.

The following definitions were used:

Serious Bacterial Infection(SBI) was defined as
- bacteremia
- urinary tract infection, or
- meningitis.
Herpes Simplex Virus (HSV) was classified as skin, eye, and mouth (SEM) if surface swabs of skin, conjunctivae, mouth, or nasopharynx were positive on HSV PCR, direct immunofluorescence assay (DFA), or viral culture.
Disseminated HSV was defined as positive HSV PCR, DFA, or viral culture in the presence of hepatitis or other end-organ damage, other than isolated central nervous system (CNS) manifestations.
CNS HSV disease was defined as a positive cerebrospinal fluid (CSF) PCR or viral culture in the absence of other end-organ damage.

WHAT THEY FOUND

Of the 183 infants were included and presented with:

124 (67.8%) pustules
57 (31.1%) vesicles, and
19 (10.4%) bullae
18 (9.8%) both pustules and vesicles.

The locations of the lesions were:

most commonly on the head (113 patients or 61.7%).
trunk (83 patients 45.3%)
extremities (80 patients 43.7%)
diaper area, (47 patients 25.7%) and
skin folds (22 patients 12.0%)

127 infants were investigated for HSV infection and the rate was found to be 7.1% ie., 9 patients. 2 cases were of disseminated HSV and both occurred in pre-term infants.

Investigations included:

Blood cultures in 105 (57.3%) of infants
Urine cultures in 71 (38.8%)
Lumbar Puncture in 61 (33.3%)
127 (69.4%) were evaluated for HSV
- 9 (7.1%) were diagnosed with HSV.
  - 7 (5.5%) had skin, eye and mouth(SEM) were in full-term infants
  - 2 (1.6%) had disseminated HSV and both cases occurred in preterm infants.

Treatment occurred in a large number of patients:

97 (53.0%) received intravenous antibiotics
81 (44.3%) received intravenous acyclovir
12 (6.5%) received oral antibiotics
81 (44.3%) received topical antibiotics.

Preterm infants (<32 weeks) had greater rates of life-threatening infections (P < .01)

9 infants were < 28 weeks
- 8 (88.9%) were diagnosed with an infection,7 of which were considered potentially life threatening:
  - 5 angioinvasive fungal infections,
  - 1 congenital cutaneous candidiasis, and
  - 1 disseminated HSV infection.
7 of the 14 life- threatening infections detected in this study were in full- term infants; in these full-term infants, SEM was the only life-threatening infection diagnosed.

Pustules or vesicles in an afebrile infant comprised 21% of all pediatric dermatology consults in this cohort. No SBI was detected that could be attributed to a skin source.

"None of the afebrile infants in our study were found to have invasive bacterial infection (IBIs), defined as bacteraemia or meningitis."

In afebrile infants with pustules and/or vesicles, noninfectious etiologies were diagnosed two-thirds of the time and infection one-third of the time, with the majority being superficial.

Life-threatening forms of infection were uncommon:

They included neonatal HSV (found in both full-term and preterm populations) and
- Skin exams of HSV infections always demonstrated vesicles or erosions.
Angioinvasive fungal infections (found exclusively in extremely preterm infants).
There were no cases of invasive bacterial infections.

With this data at hand the authors proposed a practice algorithm shown below:

Conclusion from the authors

"Full-term, well-appearing, afebrile infants <60 days of age presenting with pustules or vesicles may not require full SBI work-up, although larger studies are needed. HSV testing is recommended in all infants with vesicles, grouped pustules, or pustules accompanied by punched out or grouped erosions. Preterm infants should be assessed for disseminated fungal infection and HSV in the setting of fluid-filled skin lesions."

MY TAKE ON THIS

This is a retrospective study, although conducted in multiple centres.
There is a small sample size N = 183
It only included patients who had been seen by a dermatologist. I don't know about you but dermatologists aren't exactly plentiful in my hospital, let alone in the emergency department and they're certainly not fighting to get there.
The majority of patients were not ED patients and of the 40 seen in ED, 21 were admitted.
We can't really extend these findings to patients not seen by a dermatologist.
The investigative load on the patients was quite significant, even when seen by a dermatologist
- Nearly 60% had blood cultures
This really won't affect what I currently do.

POINTS TO TAKE AWAY

In children who are afebrile and have vesicles or pustules
- Beware the pre-term infants as they had a high number of life threatening infections
- These are all still high risk patients and should be assessed carefully
- This study doesn't change my practice, especially since we have a high level of investigations (nearly 60% had blood cultures) even in patients assessed by dermatologists and a high rate of treatment (53% received IV antibiotics and 44% received Acyclovir)

References

Sonora Y et al. Management of Pustules and Vesicles in Afebrile Infants < 60 Days Evaluated by Dermatology. PEDIATRICS Volume 154, number 1, July 2024:pp 40-47